Project Abstract Readmission to the hospital after discharge is common among elderly patients, occurring among 1 in 5 Medicare beneficiaries at an estimated cost of $12 to 44 billion per year. The Centers for Medicare & Medicaid Services has prioritized reducing readmissions with the Hospital Readmissions Reduction Program that penalizes hospitals with high readmission rates by reducing their Medicare payments. Given hospitals? incentives to reduce readmissions, many have implemented initiatives to coordinate care before and in the period following inpatient discharges, called transitional care. However, the burden of transitional care is borne by both inpatient and outpatient providers. To address this, in 2013 CMS created 2 new billing codes for transitional care management (TCM) services provided by outpatient providers within 30 days of discharge from an inpatient facility to the community. These codes reimburse for a comprehensive bundle of services to manage post-discharge care, including both a visit and non-face-to-face coordination. Preliminary analyses of these new billing codes have shown only modest use by providers. Providing the services reimbursed by TCM codes involves more than the billing provider alone, requiring allocation of resources from the medical group or provider organization. However, little is known about which provider organizations are responding to this opportunity for enhanced reimbursement for transitional care and providing TCM code services for their discharged Medicare patients. Further, it is unknown if when TCM codes are used they are affecting Medicare beneficiaries? care or outcomes after discharge. It is unclear whether visits billed through TCM codes represent new post-discharge visits that would not have happened absent this enhanced reimbursement for transitional care, or if they are merely replacing visits that would have been billed via some other means absent the availability of TCM codes. Further, while intensive transitional care interventions have been shown to reduce readmissions, it is unclear if Medicare reimbursement for a less prescriptive bundle of services can have the same effect. We propose to address these gaps in our knowledge regarding Medicare TCM code use by conducting the following analyses: Aim 1. Describe predictors and patterns of use of TCM codes among provider organizations. Aim 2. Assess the association of TCM services on post-discharge utilization, as follows: Aim 2a. Assess whether for TCM code visits substitute for other visits, or are new utilization; Aim 2b. Assess association between TCM code use and readmissions. This research will advance knowledge on how physicians respond to reimbursement changes and how resultant changes in care influence patient outcomes. The findings will inform Medicare reimbursement policy, the role of outpatient physicians and their organizations in transitional care, and the impact of outpatient physician-led coordination on patient outcomes.